Some providers may add points to the spam score. Some corporate servers may block it. You could always set up a small account with an email campaign provider

Some providers may add points to the spam score. Some corporate servers may block it. You could always set up a small account with an email campaign provider and do a small test run with a "welcome to the service" email to see how many emails get through. This assumes your members have opted into email. Your user-base may differ from the base others here have experience with, so real numbers are everything.